Tuesday, January 10, 2012

At first glance it appears to be a normal rush-hour on the Tube, with commuters listening to their ipods and reading books.

But there is one major difference: they seem to have forgotten their trousers.

The semi-naked crowds were taking part in an international event run by practical joke group Improv Everywhere.

Scroll down for video

Dressed down: Passengers on the London Underground got quite a surprise when they noticed the unconventional attire of other travellersRude Tube: Members of the flash mob act naturally as they expose their pants on the Underground

Shorts stop: Two young women travel in their underwear on the Tube as part of the worldwide trouserless event

Bare cheek: The flash mob started out at Trafalgar Square and travelled along the Bakerloo Line

Thousands of people headed to the London Underground and to subways across the world to take part in the No Trousers Tube Ride - 'No Pants day' overseas.

The annual event began with just seven participants in New York in 2001 and has now spread to 60 cities including Washington, Madrid, Toronto and Mexico City.

In London, it caught the imagination of 150 daring individuals, who divided into groups to brave the cold and fellow travellers' stares on different lines around the capital.

Participants in Toronto wore fancy dress along with their underwear as they joined in the fun for a fifth year.

Brief encounter: Participants said they were taking part both for fun and to see fellow travellers' reactions

Under wraps: Pranksters left their trousers and skirts at home but kept warm on a cold London morning by wearing cosy scarves and jackets

But the flash mobs in Madrid had more difficulty in getting some exposure for their action when the police stopped them from entering their planned starting station.

Improv Everywhere invited people to take part through Facebook, with more than 16,000 people from around the world registering to take part.

Those involved were instructed to act as they would normally on the Underground, by chatting to each other, listening to music or reading.

The idea is to entertain and surprise bystanders, and to lighten the dreariness of the daily commute by making people laugh.

No butts: Around 150 brave souls stripped off for the journey through London

Paddington bare: The British group joined a network of exhibitionists in their attempt to shock and amuse

Not everyone saw the funny side, however.

Alicia Lopez - a passenger in Mexico City, where around 700 people took part - said: 'I consider people without pants, without skirts, to be semi-naked. I don't like it.

'I don't know their demands. I don't know what they are seeking because they're protesting but I think there are ways to do it.'

Organiser Dan Becherano said the group wanted to have fun, but also to see what sort of reaction they would provoke.

'The purpose is to have fun and entertain people,' he explained. 'The purpose of flash mobs is to show how we can get together without knowing each other and work as teams without really having seen each other ahead of time.

'The most important thing will be the victims - the reaction of people who aren't involved.'

Legs go: No Pants participants attempt to keep straight faces on the New York subway, where the event began in 2001

Colour blocks: These couples show off stylish ensembles on the New York subway

Mayhem: Some more conservative onlookers in Mexico said they felt uncomfortable with the scenes on the subway

Clothes police: The mob in Madrid had to switch its starting point to Plaza de Castilla after the presence of security guards and police threatened to put a stop to the fun

On your bike: At the fifth annual No Pants day in Toronto, some even joined in the action with their bicycles